1. Field of the Invention
This invention relates generally to chart recorders, and more particularly to means facilitating the feeding of chart paper onto a drive roll.
2. Description of the Prior Art
Various ways and means have been devised to assist in guiding or threading or feeding record media onto rolls, spools, reels, or the like. Some patents dealing with this general subject matter, and which are by no means representative of all of the art which might exist in this area, are as follows:
2,551,707 Schnee May 8, 1951 2,879,993 Scozzafava March 31, 1959 et al 3,107,836 Van't Veld Oct. 22, 1963 3,611,431 Rosmanith Oct. 5, 1971 3,713,170 Kaufman Jan. 23, 1973
There are instances in which it is desirable to employ a strip chart recorder as one component of a large instrument panel. It is desirable that such recorder occupy as little vertical space as possible and that it not project significantly from the front of the overall panel. A way of accomplishing this is to provide a slide-out drawer having a chart supply box, and a chart accumulating box immediately in front of the supply box. Chart paper in the fan-folded (Z-fold) configuration is stored in the supply box and fed upward therefrom, over a chart drive roll, and downward therefrom into the accumulator box. This is fine from the standpoint of minimizing the overall height, and facilitating a comparatively flush front panel configuration, but it necessitates a comparatively great fore and aft depth of the drawer. Therefore, if the drawer is pulled out far enough for convenient insertion of a new supply of chart paper in the supply box, it is very difficult to successfully manipulate the chart so as to feed it from the supply box back into the recorder and up around the chart drive roll. If the drawer is pushed inward for greater proximity of the supply box to the drive roll, there is too little vertical space between the drive roll and the top of the drawer to enable convenient insertion of the fingers into position to facilitate guiding the paper up around the drive roll. While means can be devised to facilitate the threading of paper onto a sprocketed drive roll in the chart threading mode, such means must be properly located in the recording mode so as to not interfere with proper paper feeding. It seems that heretofore the means which were devised for convenience in chart threading, would tend to interfere with performance in the recording mode. In working with this problem, I have reached the conclusion that any permanently affixed, inflexible hardware does not lend itself to optimum chart threading/feeding, since it interferes in one mode or the other. To overcome this disadvantage, I have devised a flexible membrane type of guide or chute capable of optimum performance in both modes. The present invention solves the problem and facilitates the loading of either the Z-fold or roll stored chart onto the drive roll.